Modern trading floors seek to maximize their productivity by increasing utilization of floor space. This means that floor designers must squeeze as many traders as possible onto the floor, while providing these traders with large amounts of visual data. This data comes in the form of computer-generated text and graphical data, video feeds, and analog text feeds. While the increasing need for data drives up the number and size of these data displays, a clear line-of-sight between traders is often needed to facilitate communications between them.
The historical technology of choice for displaying the data on trading floors has been the CRT. As information needs have grown, so has the size of the CRT necessary to display that data. At the present time, CRT displays with a twenty-one inch diagonal (nineteen inches usable diagonal) is the largest display commonly used, while the seventeen inch CRT (fifteen inches usable diagonal) is the most prevalent display. Multiple monitors are frequently connected to a single host computer to allow large amounts of data be displayed, while requiring only one set of user interaction devices (such as keyboard and mouse) and a single computer.
Recently, flat panel monitors have begun to make inroads into the desktop trading market. Primarily based on Liquid Crystal Displays (LCDs), these monitors typically consume 70% less power, have smaller bezels, and are only three to six inches in depth. Because of their relatively small size, these displays allow trading desks to be made much smaller, and they can be mounted in ways which are difficult and costly with CRTs. Unfortunately, LCD monitors are still quite expensive.
As mentioned earlier, multi-head displays are quite common in the desktop trading market. Typically, multiple graphics cards are inserted into the host PC, each driving one monitor. Alternatively, specialized multi-head graphics cards are available which can drive two or four heads simultaneously. Both of these methods have substantial drawbacks. The first suffers in that the limited number of computer bus slots (usually only three PCI-style) available in a typical PC are squandered by the graphics cards. The limited number of bus slots means that only three heads may be connected to a single PC using this method. The second method suffers because the specialized multi-head graphics cards are quite expensive, and tend to lack features present in leading-edge single-head cards. One such multi-head card actually provides on a single card the circuitry normally found on two graphics card in order to drive two displays.
In addition to the need to selectively and independently provide a large quantity of video data on several video display terminals, it is desirable to merge plural video data sources of varying formats into a single video data stream, and to make that integrated data stream selectively and independently available to a variety of video display devices, including devices having varying requirements for input video data format.